Conduit for electric cables or conductors.



No. 801,774. PATENTED OCT. 10, 1905. T. E. DEVONSHIRE. GONDUIT FOR ELECTRIC GABLES OR CONDUCTORS.

APPLICATION FILED NOV.5,1904.

2 SHEETSSHEBT 1.

WITNESSES INVENTOR ATTO R NEYS No. 801,774. PATENTED OCT. 10, 1905;

T. E. DEVONSHIRE. GONDUIT FOR ELECTRIC GABLES 0R OONDUGTORS.

APPLICATION FILED NOV. 5, 1904.

2 SHED S-SHEET 2. 0 0 da 9 (J 5 WI NESSE I INVENTOB T 8 23mm a. 50. W

MM Mun/WW ATTO RN EYS UNITED [STATES PATENT OFFICE.

CONDUIT FOR ELECTRIC CABLES O'R CONDUCTORS.

Specification of Letters Patent.

Patented Oct. 10, 1905.

Application filed November 5, 1904. Serial No. 231,522.

T 0 all whom, it may concern.-

Be it known that I, THOMAS EASTON DEVON- SHIRE, civil engineer, a subject of the King of Great Britain and Ireland, residing at Suffolk House, Laurence Pountney Hill, in the city of London, England, have invented new and useful Improvements in Conduits for Electric Cables or Conductors, of which the following is a specification.

My invention relates to conduits for electric cables or conductors, the said conduits being of the type in which perforated or reticulated metal or metal in analogous form, such as the form known as expanded metal, is combined with cement-mortar or concrete or the like; and the object of my invention is to make the length of which the conduits are formed so that while they have great strength and durability and can be economically and quickly made they are protected against injury at angles or edges and thejoints of the said lengths offer no obstruction to the drawing of the cables through the conduits. In the construction according to my invention the edges, which would otherwise be liable to injury, are protected by metal, and at each end of the lengths the ducts terminate in an internal metal end piece or fer rule, so shaped, as hereinafter described, as to prevent any obstruction being presented to the drawing of the cables through the conduits. For simplicity of description I will refer to the perforated, reticulated, or like metal as expanded metal, and I will referto the cement-mortar or concrete or the like as cement, it being understood that in these expressions I include all descriptions of the respective materials which can be used. The surfaces of the adjacent lengths of conduit are preferably made with the intervention of metal, such as lead, which is in contact with the expanded metal at the adjacent ends of the lengths of conduit, so thatthere is metallic continuity throughout the conduit, and an earth-sheath is thereby formed to protect the cables or conductors in the conduit from extraneous currents. 1

In the accompanying drawings, Figure 1 shows the spigot end. Fig. 2 shows the socket end separated. Fig. 3 shows the two joined together, and Figs; 4, 5, and 6 are like views showing the invention applied to a multipleway conduit.

Referring to Figs. 1, 2, and 3, the exterior of the socket end is covered by a metal casing, as shown at (1, whose outer edge may be made plain, as shown, or be made to overlap the outer edge of the socket, as at a in Fig. 1, to protect it. The expanded metal I), which strengthens the cement 0, extends from the opposite end of the length (namely, the spigot end) and abuts against'the metal casing a. Inward of the socket and inside the conduit end is the metal end piece or ferrule d, with an outwardly-curved outward part, as shown at (1 The spigot end is provided with a imilar metal end piece or ferrule (i with an utwardly-curved outer part (1*, covering the outer edge of the metal ring g of the spigot end. The joint may be made perfect by coating the meeting surfaces of the spigot and socket, or both, with cement or pitch or the ike.

At the socket end the metal casing a may overlap the edge, as sh wn at a and the end portion of the expande metal is confined between it and the interior metal end piece or ferrule (Z, which has a rounded edge at til At the spigot end the end of the expanded metal I) is confined between the metal end piece or ferrule (Z"(with the'outwardly-curved outer part d) and the metal ring 0, which is recessed to receive the edge of the socket and make a flush exterior to the conduit at the exterior of the joints.

Between the outer end of the metal end piece or ferrule d at the socket end and the overlapping edge a is inserted an inclined ring f, of soft metal, such as lead. A correspondingly-inclined ring g, of soft metal, such as lead, is inserted between the outer part (2 of the metal end piece or ferrule d and the ring e. These rings f and g being in close contact with the expanded metal and when the lengths are put together being in close contact with each other give metallic continuity throughout the length of conduit,

so as to constitute an earth-sheath, protecting from extraneous currents the cables or conductors in the conduit.

The invention may be applied to single-way conduits and to conduits with two or more ways in them.

When the form shown in Figs. 1, 2, and 3 is applied to conduits having two or more ways through them, the socketand spigot ends, with the lead or like rings f and g, will be made of the flattened elliptical or other shape of the conduits with two or more ways, and metal end-pieces or ferrules can be formed with metal plates, as shown at d (i in Figs. 4, 5, and 6, (which are drawn to a smaller IIO.

scale,) the said plates having formed in them openings of the same bore as the ways in the conduits and with outwardlyburved portions at d and d for the purpose aforesaid.

I claim as my invention Lengths of conduit for electric cables, the said lengths being made of combined openwork metal and cement-like material, with socket and. spigot ends, and provided at each end of the way through them with internal metal end pieces or ferrules having outwardlycurved portions at the end, and with metal In testimony whereof I have signed this specification in the presence of two subscribmg witnesses,

THOMAS EASTON DEVONSHIRE.

Witnesses:

1,. W. HAMILTON, T. G. MOWAR. 

